"We recently [found out] that Kolkata had a big special screening of This is Us, they all went mad over it," the group said. "We know about Bollywood life, and would be glad to do a number for any Bollywood film."

The band said that their recently-released documentary was a way of connecting with fans around the world, adding: "The Directioners are our wealth.

"We like to be connected to them, and they are the ones who've made us No.1 in 37 countries."